Shastina and the Mount Shasta Landslide, California

California's magnificent volcano, Mount Shasta, has a satellite (or
parasitic) cone on its western flank called Shastina. If Shastina were a
solitary peak, it would still be the third highest peak in the Cascade Range
with an elevation of 12,330 ft (3,758 m). However, it is overshadowed by Mount
Shasta, nearly 2000 feet higher.

Shastina has a very fresh looking crater and is obviously recently active.
The small hills in the distance beyond Shastina are great blocks that slid
downhill in a huge landslide about 300,000 years ago. Despite their impressive
size, volcanoes are weak piles of lave flows, mudflows, and ash layers, and are
weakened further by corrosive gases from the magma. After Mount Saint Helens
collapsed in 1980, geologists began to wonder how often collapses like that
happened. The answer is, quite often. The hilly terrain northwest of Mount
Shasta was soon recognized as one such landslide.

It is probably no accident that Shastina is located in the direction of the
slide. After the volcano collapsed, it was easier for magma to escape through
the broken flank of the volcano than through the old summit.

The snow patches on Shastina conceal a couple of tiny ponds that remain
frozen until very late in the summer. Even in this picture, taken late in July,
they are still covered with snow and ice.